The present invention relates particularly to a surgical prosthetic vessel graft and catheter combination, and to a method of installing such a graft. The combination and the method are particularly useful for the repair of blood vessels, and particularly for major arterial vessels such as the aorta.
A relatively serious and fairly common health problem involves the development of diseased conditions in major artieries of the body, particularly the aorta. Such problems frequently take the form of a weakened section of the artery and the development of an aneurysm (a localized abnormal dilation). The weakness which results in the aneurysm is frequently indicative of a serious risk of arterial hemorrhage.
One preferred treatment for such a condition is the surgical removal and replacement of the section of the vessel containing the aneurysm with a graft prosthetic vessel. This has become a fairly common procedure. However, there are serious technical problems with the procedure as commonly practiced. One requirement for the operation is that some occlusion means must be provided for preventing loss of blood during the removal of the defective vessel section and the substitution of the graft. The most obvious procedure is to simply use clamps to occlude the vessel on both sides of the graft site before the defective section is removed and while the graft is being attached, and to then remove the clamps after the graft has been secured.
This procedure involves serious difficulties, and risk of damage to the adjacent portions of the vessels which are clamped, particularly in cases of severe arteriosclerotic vessels. In a patient who has developed an aneurysm, the adjacent vessel sections are often weak and arteriosclerotic, and may actually be cracked or damaged by the occulsive clamps. Also, the use of the clamps may dislodge plaques which are common within the arteries of patients having arteriosclerosis, increasing the risk of forming an obstruction. The risk of damage to the artery from clamping is especially serious if calcification has developed in the interior of the artery. In such an instance, placing the clamp on the vessel may cause the calcium to break up, risking rupture of the vessel, or damage, from the broken calcium, and causing the broken calcium particles to tend to move in the artery, and to possibly act as an occluding embolus.
In order to avoid the problems associated with clamping, it has previously been proposed to provide an occluding balloon catheter. Such a catheter, and the use of such a catheter for vascular surgical repairs is disclosed in U.S. Pat. No. 3,833,003 issued on Sept. 3, 1974 to Alfred Taricco for an "INTRAVASCULAR OCCLUDING CATHETER". When such a device is used, it is inserted through an incision in the wall of the vessel, preferably on the upstream side of the defect, and then a balloon collar on the end of the catheter is inflated through the catheter tube so as to occlude the vessel to prevent bleeding during repair. Preferably, a second catheter is also inserted and inflated in the vessel on the opposite side of the defect to be repaired. The balloon catheter has the major advantage that the clamp formed by the balloon is form fitting to the internal shape of the vessel, and is gentle yet firm, and does not have nearly as much potential as a clamp for damage to the vessel wall. After the repair is completed, the balloons of each of the balloon catheters are deflated, and each catheter is removed through the incision where it was inserted. Each of the incisions must then be closed. These last mentioned incisions, and the necessity for closing these incisions in the vessel walls presents a disadvantage which it would be very desirable to overcome.
Accordingly, it is one object of the present invention to provide, in the instance where the repair consists of the insertion of a prosthetic vessel graft, a combination device and method which avoids the necessity for sewing up two incisions in the wall of the vessel where the catheters have been inserted.
It has also been recognized that, in addition to avoiding loss of blood during vascular repairs, it is very desirable to provide for a shunt flow of blood around the diseased vessel portion which is to be repaired or replaced in order to minimize trauma to the parts of the body which would normally be provided with blood through the diseased portion. This problem has been addressed previously by shunt catheters which include balloon collar means for attachment. Such devices are disclosed, for instance, in U.S. Pat. No. 3,435,824 issued Apr. 1, 1969 to Herminio Gamponia for a "SURGICAL APPARATUS AND RELATED PROCESS" and also in U.S. Pat. No. 3,516,408 issued June 23, 1970, to Vincent Montanti for an "ARTERIAL shunt".
In the devices illustrated in each of these patents, a shunt tube is provided with a balloon collar at each end. The ends are inserted through incisions in the artery on opposite sides of the defect, and inflated to isolate the defect and to permit the passage of blood through the shunt. After the repair has been completed, the balloons are deflated and the ends of the tubes are removed through the incisions through which they were inserted and the incisions are sewed up. Again, the repair of these incisions in the walls of the vessel being repaired represent a serious disadvantage, particularly in a patient whose vessels are weak and diseased.
Accordingly, it is another object of the present invention to provide for a shunt catheter and prosthetic graft combination and method where the necessity for repairing incisions made for insertion of the ends of the catheter in the walls of the vessel is avoided.
Another problem in conjunction with the use of a shunt catheter of the type referred to immediately above is that the flow of blood through the shunt is not controllable. Thus, during the interval when the upstream end of the shunt is attached, and the downstream end is not yet attached, blood can be lost through the shunt device itself. Furthermore, there may be a need for arresting blood flow through the shunt device while further repairs downstream of the shunt are made.
Accordingly, it is another object of the invention to provide for a shunt device combination and method in which blood flow through the shunt may be controlled, at will.
One of the portions of the vascular system which often requires repair is at the bifurcation of the aorta at the intersection with the iliac arteries. Furthermore, in the present practice it is common to provide a prosthetic vessel graft for that bifurcated portion of the aorta artery. In such an operation, the prevention of blood loss and the provision of the shunt function is much more complicated. The above mentioned Gamponia patent disclosed a bifurcated bipass device, which presumably might be suitable for repair of the bifurcated portion of the aorta. However, the use of such a device would involve the necessity for repairing three separate incisions for the insertion of the three separate ends of the shunt, after the operation, and no means is provided for the prevention of loss of blood when using the Gamponia device after one or two of the device ends have been attached, and before the last one is attached and secured by its balloon collar.
Accordingly, it is another object of the invention to provide a device combination and a method which are particularly useful for the installation of a prosthetic graft to replace the bifurcated portion of the aorta.
Further objects and advantages of the invention will be apparent from the following description and the accompanying drawings.